Superbodied oils



22, 1967 c. E. PENOYER 3,337,593

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United States Patent 3,337,593 SUPERBODIED OILS Charles E. Penoyer, Chagrin Falls, Ohio, assignor to The Sherwin-Williams Company, a corporation of Ohio Filed Dec. 9, 1963, Ser. No. 329,197 11 Claims. (Cl. 260-407) This invention relates to extraordinarily high viscosity oils derived from unsaturated fatty oils, particularly drying oils of the natural or synthetic types which oils are characterized by freedom from gel particles and false body. More particularly, the present invention relates to a method for producing superbodied oils having viscosities in the range of from about 20 minutes to about 75 minutes, Gardner-Holdt, herein characterized as superbodied oils. It is to be understood that the viscosity value referred to herein is based upon the time required for an air bubble to travel the length of a standard Gardner varnish viscosity tube under standard temperature conditions (77 F.).

' Still more particularly, the present invention is an improvement upon the invention of James A. Arvin described and claimed in Patent No. 2,607,784.

It has been found that unsaturated fatty oils (unsaturated fatty acid polyesters) when bodied at atmospheric pressure to the point of incipient gellation and thereafter blown with steam to a high body, e.g. one hour or more, develops a gel structure which is detrimental in coating compositions. False body is another difficulty attendant 'superbodied oils. This false body is believed to be due to the presence of intramolecular attraction forces (Van der Waals forces) which upon dilution with a thinner, solvent, or other additive, e.g. fatty acid or rosin, are dissipated with the result that the viscosity, or body, of the oil decreases more than is accountable to the dilution effect of the added material. Durability of the film is related to the actual body of the oil, and when an oil exhibits false body this relationship is destroyed and it is not possible to estimate the durability on the basis of viscosity. However, when the oil possesses a true body in the range of from 20 to 75 minutes, which body results from the development of intermolecular carbon-carbon bonds through polymerization of the mass, then the relationship of durability to oil body is such as to enable estimation of the durability of a coating composition containing such oil to a much better degree.

The procedure of the invention varies from that described and claimed in the aforementioned Arvin patent in several important respects. First, the bodying operation hereof is carried out under vacuum instead of at atmospheric pressure. Secondly, according to the improved process, moisture is introduced into the bulk of the oil from and after arrival at the point of incipient polymerization instead of from and after arrival at the point of incipient gellation, and continued in the process until the desired body is reached. When these changes are made in the Arvin process, there results a bodied oil which is free of gel particles, or nucleii, which interfere with the later processing of coating compositions and the shelf-life of the product. Moreover, these products are characterized by true body as distinguished from false body.

As indicated above, there is a relationship between viscosity and the durability of a coating composition containing a highly bodied oil having a true body or viscosity in the range of from 20 minutes to 75 minutes. Although 'I do not wish to be bound to any theory for explaining such relationship, it is believed that in a normal oil of the drying type when applied as a paint film, most of the hardening is brought about by reaction of the oil with oxygen, i.e. oxidative polymerization. Even in those cases -where partially bodied oils are utilized as the binder, or

vehicle, for the pigment, the major portion of the hardening reaction is brought about by cross-linking of the molecules with oxygen. The predominance of oxidative polymerization in the process of film solidification yields a product which is subject to decomposition, e.g. on exposure to actinic light, which leads to degradation of the film. Oxidative products of polymerization are more susceptible to deterioration than condensation products having carbon-to-carbon bonds. To increase the ratio of the more stable carbon-to-carbon bonding in the final solidified products with a corresponding reduction in the amount of oxidative polymerization which is permitted to take place, it has become the practice to body the oils by heating, or by means of a catalyst. Such bodied oils may be cut with a thinner to a suitable viscosity, and when applied and the thinner removed by vaporization, the resultant coating composition film is well along the way to solidification due to the preliminary carbon-to-carbon polymerization. The limit of prebodying oils has heretofore been determined by the occurrence of gellation in the course of such processes and the difficulty of applying protective coatings based thereon. The presence of gel particles within the bulk of the oil seemed to promote further solidification or gellation of the mass prior to application and hence instability of the product on the shelf. The presence of such particles initiates the gellation reaction.

Briefly stated, the present invention is in a method of making a superbodied unsaturated fatty oil free from gel particles and false body having a viscosity in the range of from 20 minutes to about minutes, Gardner-Holdt,

which comprises the steps of heating a body of the oil under subatmospheric pressure to the temperature of incipient polymerization, i.e. the temperature at which any increase in temperature causes a significant or practical increase in the body, .or viscosity, of the oil. Generally, this temperature is in the neighborhood of about 475 F. to about 525 F. and may be specifically predetermined in the laboratory for any oil. At or just below this point, the bulk of oil is brought into contact with water vapor, for example by the introduction of water, or steam, into the hot body of oil. Thereafter, the temperature of the oil is increased to initiate and sustain polymerization of the oil, i.e. bodying of the oil, while continuously contacting the oil with water vapor. Heat induced polymerization of the oil is continued to a maximum temperature of about 6 15 F. for a period of time suflicient to increase the viscosity of the oil to from 20 minutes to about 75 minutes, 'Gardner-Holdt, while continuously contacting the body of oil with water vapor. When the viscosity has been determined to be at the desired point by periodic sampling or by prior determination of the required amount of time toreach a desired body at a given temperature, the contacting of the body of oil with moisture is discontinued. Thereupon, the oil is checked by suddenly dropping the temperature to below the temperature of further polymerization for the oil. Checking is a term of art for arresting polymerization and is achieved by a rapid reduction in the temperature of the batch, to a temperature below which further polymerization does not occur. This is usually below about 475 F.

The annexed drawing diagrammatically illustrates com- The presence of a catalytic amount, i.e., 0.1% to about 2% by weight of the oil of such a material has been found to confer several important properties on the nature of the reaction and on the final product, both of which can be utilized with advantage. The presence of such metallic salts in such low amount in the oil, alone or in combination with a lead salt of a similar acid material and also soluble in the oil, has been found to cause a desirable in crease in the amount of hydroxyl bearing components in the final oil. The lead salt may also be used alone for this purpose but with a somewhat lower degree of effectiveness. Increased hydroxyl content, as hereinafter more particularly pointed out renders such oil highly useful in the production of oil-in-water emulsions from such high viscosity oils. Thus, there may be used the sodium, potassium, lithium, cal-cium, magnesium, barium, strontium and lead salts or mixtures of such salts, of high molecular weight aliphatic, saturated or unsaturated, fatty acids containing from to 22 carbon atoms or more, and including cycloaliphatic acidic materials, such as isodecanoic, dodecanoic, ricinoleic, stearic, oleic, linoleic, linolenic, naphthenic acid, rosin acids, dimer fatty acids, e.g. dimerized linseed oil fatty acids, etc. When a lead soap is used alone or in conjunction with the alkali or alkaline earth metal soap, it is present in an amount generally in the range of from about 0.05% to about 2% by weight of the oil. The lead soap, if used with a cooperating soap, may be added along with the cooperating soap or at a different time in the bodying cycle. It has also been found that suitable salt materials of this character soluble or dispersible in the oil may be formed in situ by adding to the polymerization batch an oxide of the metal, for example calcium oxide, magnesium oxide, barium oxide, lead oxide, or a carbonate, e.g. calcium carbonate. Increase in the organic hydroxyl content of the final oil is readily ascertained from infrared analysis of the final product. With respect to the salt additions, it is the presence of the metallic moiety in a form soluble or dispersible in the oil rather than the specific nature of the organic acid moiety which is important.

It becomes convenient at this point to illustrate the process of the present invention in considerable detail by giving a specific example of the production of a bodied vegetable drying oil made from an alkali refined commercially available linseed oil material. While it is desirable that the base oil be of high quality as represented by an alkali refined, bleached and refrigerated product, raw linseed oil may be used. In any case, the starting material should be without a tendency upon heating at high temperature such as 585 F., especially in the presence of steam, to precipitate solid substances. Raw vegetable oils should be so conditioned prior to and/ or in the bodying process that they do not precipitate or break out solid substances commonly contained in these oils. The processes for such conditioning are well known in the art. The base oil should preferably have, but not necessarily so, a low free fatty acid content and a light color. Any of the common drying oil materials alone or in combination with each other, and including long oil modified synthetic resins as long oil modified alkyd resins, etc. may be used. Thus, linseed oil, dehydrated castor oil, soybean oil, safilower oil, tung oil, perilla oil and mixtures of such oils may be used as well as the corresponding oil modified alkyd and polyester type resinous materials. Copolymerized drying oils including styrenated drying oils, e.g. styrenated linseed oil, which oils are Well known in the art, may also be used in accordance with this process.

Utilizing an apparatus such as diagrammatically shown in the annexed drawing, and with alkali refined, bleached and refrigerated linseed oil as an example, a quantity of this oil is heated in a varnish kettle while mechanically agitating under a vacuum of at least about 24 of mercury to a temperature just below that where significant polymerization takes place, e.g. 450 F. At this point, the mass has arrived at incipient polymerization and further increase in temperature causes polymerization and an increase in viscosity. It is preferred that carbon dioxide, or nitrogen, or other inert gas be passed through the linseed oil during the heating from the starting temperature (room temperature) to about 450 F. When the temperature has reached 450 F. just prior to the onset of homopolymerization which causes an increase in viscosity, it is preferable to substitute steam for part or all of the carbon dioxide or other inert gas. The application of steam to the body of oil may be through a conventional bubble ring, or by mere introduction through pipes located at the bottom of the container. The flow of steam through the entire mass of oil is maintained throughout the remainder of the polymerization operation. During the last half hour of the operation, it may be found desirable that an inert gas such as carbon dioxide or nitrogen be substituted for the steam again to provide a purging of the oil of any substantial amount of residual moisture.

The temperature of the oil is increased while the application of steam is continued until a bodying temperature of about 575 F. is reached. The mechanical agitation and steaming are continued as the bodying temperature is maintained until a viscosity of about 45 seconds is achieved at which point the vacuum is temporarily released, and about 0.29% by weight of the original oil of a mineral spirits solution of lead isodecanoate containing 24% lead, and 0.44% by weight of lithium naphthenate, containing 1.4% lithium, are added. This addition is not absolutely required for the operation of this process, but it has been found advantageous in that it aids the development of emulsifiability of the final product. In general, the amount of alkali metal or alkaline earth metal added as a soap soluble or dispersible in the oil is generally from about 0.002% to about 0.010% by weight of the oil, when calculated as the metal.

The conditions of bodying are maintained as above described until a viscosity of approximately 12 minutes is reached. This viscosity marks a stage in the bodying process where operating temperatures are desirably dropped to lower levels and extreme care taken to avoid excessive local overheating. Excessive local overheating has beeen found, despite the steam treatment, to promote the formation of irreversible gel particles. Accordingly, it is recommended practice that at this point of viscosity development to drop the temperature, for example, from about 580 F. to from about 545 F. to 560 F. At this point, the mass has a viscosity of about 20 minutes, and the elapsed time in reducing the temperature of the mass has been about 30 minutes. The temperature of the batch is then allowed to drift slowly downward until ultimately a temperature of only about 470 F. is reached and the final viscosity is about 52 minutes. At this point, the batch is suddenly cooled to about 450 F. using water in a coil immersed in the oil or any other suitable cooling means. Upon reaching the temperature of about 450 F., the pressure upon the batch is increased to atmospheric, and the entire quantity of bodied linseed oil is pumped in about 5 minutes elapsed time to a predetermined quantity of reducing solvent in a conventional scale tank equipped with a water cooled solvent reflux condenser and further provided with a mechanical agitator. This equipment provides a rapid general reduction of the hot oil with the solvent.

This procedure produces a bodied alkali refined linseed oil having a viscosity before reduction of 52 minutes, Gardner-Holdt. This viscosity will not show change on the addition of solvents followed by removal thereof, nor will the reduction in viscosity by the addition of fatty acids or rosin acids be more than can normally be accounted for by such dilution. In the case of an oil having false body, the addition of rosin acids or fatty acids or solvent to the material will result in a reduction of viscosity which is far greater than would be expected by such dilution. In fact, this is one of the methods for testing for false body.

In a second example for the production of a high polymer linseed oil having a viscosity of from 50 to 60 minutes, Gardner-Holdt, the following procedure is followed. The cooking kettle, such as the kettle shown in FIG. 1 in diagrammatic form, is charged with 3700 pounds of an alkali refined, refrigerated linseed oil. The batch is agitated with carbon dioxide, and vacuum applied to the extent of about 28" of mercury. Heat is applied for a period of about 2.75 hours until the temperature reaches about 450 F. At this point, steam is introduced into the body of the oil through a plural vent pipe located at the bottom of the tank, the rate of steam flow through the body of oil being determined by the tendency for loss of oil through the vapor vent at the top of the kettle, the rate of flow being regulated to prevent such loss. Carbon dioxide is blown through the body of the oil simultaneously with the steam. The vacuum is held at 28" of mercury, and the temperature elevated to about 575 F. The heat is held at this point with a minimum rate of heat input into the apparatus. The temperature reaches about 575 F. in about.65 minutes time and is held at this temperature until a viscosity of from 40 to 50 seconds is obtained. This takes a period of time of about 7 hours and minutes.

At the 40 second viscosity, all heat input is terminated, and the vacuum released. The vacuum pump is kept operating, and the steam blow is reduced, if necessary, to maintain proper level of the oil in the kettle. At this point, 10.75 pounds of a mineral spirits solution of 24% lead isodecanoate is added very slowly and carefully. Immediately thereafter, 16.25 pounds of a lithium naphthenate dispersion in water having a lithium metal contentof from l.21.6% lithium is added. This solution contains some water and will tend to crackle slightly on mixing with the hot oil. After the addition has been completed, the tank is again sealed, and the vacuum slowly and carefully reapplied to 28" of vacuum. Maximum steam blow .is again obtained, and the batch held under these conditions for a viscosity of from 7 to 8. minutes. At this point, the temperature is dropped to about 550 F. It has been predetermined for this particular oil that viscosities in this range are critical beyond which the thermal homopolymerization of the linseed oil will become uncontrollable at 575 F. The heat is now allowed to fade to about 550 F. by cutting off one of the heat input burners. Cooling water may be introduced through the cooling coil intermittently, if necessary. About 30 minutes later, the temperature has achieved 550 F., and the viscosity is determined to be about 9 minutes, Gardner- Holdt. All heat input is terminated and the vacuum released. The vacuum pump is maintained operative in order to provide a slight negative pressure so fumes from .the kettle go through the pump. Foaming caused by the steam should have subsided at this viscosity. At this point, there are slowly added 36 pounds of glycerin, or other vpolyhydric alcohol containing from 3 to 10 carbon atoms and at least 3 hydroxyl groups such as, pentaerythritol, dipentaerythritol, trimethanol ethane, trimethylolpropane, tn'ethanol ethane, sorbitol, mannitol, etc. The addition of the polyhydric alcohol should be done over a period of about 30 minutes. When the addition has been completed, the kettle is again closed, and the 28" vacuum slowly and carefully reapplied.

' After the body of the oil has reached about 14 minutes, Gardner-Holdt, samples are then taken every 15 minutes. About 60 minutes after the attainment of the 9 minute viscosity, the viscosity is found to have increased to 24 minutes. At this point the burner flame is reduced and heat allowed to fade to about 500 F. While maximum steam blow and 28" mercury vacuum are maintained. These conditions are maintained until the body of the oil has reached about 45 minutes, Gardner-Holdt, occupying a time period of an additional 90 minutes. The heat is maintained at about 500" F. until the viscosity has reached about 51 minutes, Gardner-Holdt.

At this point, the batch is check by putting cold water through the kettle cooling coil and dropping the temperature sharply to 450 F. After an additional 40 minutes, the viscosity of the oil is 54 minutes, Gardner-Holdt, and the temperature of the batch is 450 F.

Prepartion is then made to drop the oil into a thindown tank, the transfer line from the varnish kettle to the thin-down tank being preheated with steam, and the reflux condenser above the thin-down tank cooled with water. The thinner into which the oil is dropped may consist of 100 pounds of mineral spirits in the tank.

In transferring the bodied oil to the thin-down tank, the steam being blown through the bodied oil is turned off, the vacuum released, and carbon dioxide maintained in the varnish kettle. Then the contents of the varnish kettle are pumped at a temperature of about 450 F. to the thin-down tank.

The thin-down tank is provided with an agitator, and is desirably equipped so that the tank and contents can be Weighed. A tare weight of the thin-down tank with 100 pounds of mineral spirits in it is taken before pumping the oil into the tank, and this substracted from the total weight of the tank and contents after the oil has been pumped into it. This gives the total weight of oil in the thin-down tank. An additional quantity of mineral spirits is pumped into the tank on top of the oil amounting to 7% by weight of the oil minus the 100 pounds of mineral spirits that are already present in the tank. An additional solvent, ethyl ether of ethylene glycol in the amount of 3% by weight of the oil is then pumped into the thin-down tank, and the entire mass agitated and circulated for a period of an hour. The contents are .then

pumped into a storage tank.

Superbodied linseed oils produced in accordance with the foregoing procedure have acid values in the range of from about 5.5 to about 9.0, 7.8 being normal. The viscosity of the reduced product at 77 F., Gardner-Holdt, is 2 minutes to 4 minutes. The color of the reduced product is in the range of 4.5 to 7.5, Gardner; the weight of the material per gallon at F. is in the range of from 8.0 to 8.1, with 8.05 being normal. The specific gravity of the reduced product at 75 is 0.959 to 0.972. The nonvolatile material content of the reduced product is in the range of from 90.5% to 91.5%.

The characteristics of the superbodied oils in the unreduced state show the following values. The acid value is, in general, 6-10, with 8.5 being normal. The viscosity at 77 F., Gardner-Holdt, is normally 50-60 minutes. The color of the unreduced product is in the range of from 5 to 8, Gardner. The weight per gallon at 75 F. is in the range of from 8.1 to 8.2 pounds per gallon. The specific gravity at 75 is in the range of from 0.972 to 0.9836. The non-volatile matter content is 100%, 'and the iodine value is 80 to 100.

Instead of ethylene glycol monoethyl ether, there may also be used the methyl ether of ethylene glycol, or the isopropyl ether of ethylene glycol.

The foregoing superbodied alkali refined linseed-oil is particularly suitable for emulsification to form an oil-inwater emulsion which, in turn, has particular utility in the manufacture of outside house paints by conventional techniques for forming coating compositions from emulsified vehicles. It is important to keep the non-volatile solids content .of the superbodied oil as high as possible, desirably above 80% solids, and preferably about in order that the ultimate solids content when the superbodied oils are used in paint latices, will enable maximum latitude in paint formulation.

Instead of linseed oil, which is a widely used coating composition vehicle, there may be used another drying oil whether natural or synthetic and long oil modified synthetic resins. These oils are preferably break free or rendered so by suitable conventional pre-treatment. Thus, there may be used in this process, dehydrated castor oil, soya bean oil, safflower oil, perilla oil, tung oil, ioticica oil, tall oil drying oils, styrenated linseed oil, styrenated tall oil, long oil modified alkyds, such as linseed/glycerol/ phthalic anhydride, oleoresinous varnishes, such as linseed/maleic/r-osin varnishes, etc. These are specific examples of materials contemplated by the term unsaturated fatty oils as used herein. These oils may be used alone or in admixture with .other oils. For example, a superbodied linseed oil/soya bean oil/dehydrated castor oil material 2:2:1 having a viscosity of 5060 minutes, Gardner-Holdt, has been prepared by this process.

It has been found that by utilizing continuous steam blow from the point of incipient polymerization instead of from the point of incipient gelation makes the matter of control at the point of incipient gelation much less critical. Controls applied against actual gelation at the point of incipient gelation often fail and cause the oil to gel beyond the point of recovery especially in the course of commercial large scale bodying operations. Any gelation which does occur at this stage of the manufacture provides particles of gel which adhere to the walls and other surfaces of the equipment. Some of this adhesion occurs at the interface between the oil and the atmosphere above the oil where it tends to decompose to some extent to contaminate the product with solid particles and cause a darkening of color. Other particles form within the mass of the oil and adhere to the body of the vessel where, because of local overheating, the gelation is carried well beyond the point where the gel may be reversed and put into solution. Thus, particles are formed in the body of the oil which unless removed cause a seediness in the paint in which the oil serves as a vehicle. When steam blowing is not employed throughout the bodying operation, an excessive free acidity tends to develop in the oil. These acids are difficult or impossible to remove from the oil by distillation after the oil has passed through the stage of incipient gelation.

As indicated above, sub-atmospheric pressures are employed throughout the bodying of the oil in accordance with the present process. One reason for employing such sub-atmospheric pressures is to distill monomeric acids as soon as they are formed, leaving polymeric acids behind in the oil for partial esterification of the polyols introduced, and the polyols which are formed by thermal decomposition of the oil. Where a polyol addition is made, it is not made until a substantial degree of polymerization of the oil has been accomplished. The partial ester of the polymeric acids yields a preferred type of surfactant for subsequent emulsification of the superbodied oils. This desired objective of promoting partial esterification with polymeric acids and avoiding, to as large an extent as possible, an esterification reaction with monomeric acids, is best accomplished under vacuum. The removal of monomeric acids from the oil is accomplished as rapidly as possible under vacuum, and such removal is further aided by the continuous passing of steam through the oil. Substanital vacuum generally in the range of from 24 to 30" of mercury are useful herein, with a vacuum in the range of 26" to 29" being preferred.

Still further, if a substantial vacuum is not employed throughout the bodying operation, an excessively high fatty acid content of the oil results and poor final drying of a coating composition film resuults because of the greater content of essentially non-drying fatty acids. A high degree of fatty acidity may also result in a vehicle which is excessively reactive with reactive pigments, such as, zinc oxide. The conduct of this process under subatmospheric conditions also results in improved color of the final product. Ordinarily, an oil becomes quite dark in cooking because of the development of oxidative decomposition products. The odor is also better which is highly desirable for superbodied oils to be used in coating compositions. Many of the decomposition products which are formed in the course of the bodying reaction are water sensitive, and such water sensitivity is imparted to the final film of a coating composition containing such ma terial unless these water sensitive components are removed by vacuum distillation in the course of bodying the oil.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or the equivalent of such be employed.

It is, therefore, particularly pointed out and distinctly claimed as the invention:

1. A process for making a superbodied unsaturated fatty oil free from gel particles and false body, and having a viscosity in the range of from 20 minutes to 75 minutes, Gardner-Holdt, which comprises the steps of:

(a) heating a body of said oil under subatmospheric pressure to the temperature of incipient polymerization for said oil,

(b) contacting said body of oil with water vapor at said temperature,

(0) increasing the temperature of said body of oil to a maximum temperature not in excess of about 615 F. to initiate and sustain thermal polymerization of the oil while continuously contacting the body of oil with water vapor,

(d) maintaining the body of oil under thermal polymerization conditions until the viscosity of the oil reaches a maximum viscosity in the range of from about 20 minutes to about 75 minutes, Gardner- Holdt, while continuously contacting the body of oil with water vapor,

(e) discontinuing the contacting of said body of oil with water vapor, and

(f) checking the oil by rapidly dropping the temperature to below that required to sustain thermal polymerization.

.2. The process of claim 1 in which the unsaturated fatty oil is linseed oil.

3. The process of claim 2 in which the linseed oil is an alkali refined linseed oil.

4. The process of claim 1 in which the unsaturated fatty oil is a mixture of alkali refined linseed oil, dehydrated castor oil, and soya bean oil in a weight ratio of about 2: 1:2.

5. The process of claim 1 in which the body of oil is contacted with water vapor by blowing the body of oil with steam.

6. The process of claim 1 in which from about 0.1% to about 2% by weight of the oil an alkali metal soap of an organic acid, which soap is soluble in the oil, is added to the body of oil during polymerization.

7. The process of claim 1 in which from about 0.1% to about 2% by weight of the oil an alkaline earth metal soap of an organic acid, which soap is soluble in the oil, is added to the body of oil during polymerization.

8. The process of claim 5 in which the soap is added in admixture with a lead soap of an organic acid, which lead soap is soluble in the oil, said lead soap being present in an amount ranging from about 0.05% to about 2% by weight of the oil.

9. A process for making a superbodied alkali refined linseed oil free from gel particles and false body, and having a viscosity in the range of from 20 minutes to 75 minutes, Gardner-Holdt, which includes the steps of:

(a) heating a body of said oil under a pressure of from about 5 mm. to about mm. of Hg to a temperature of about 450 F. while blowing the body of oil with an inert gas,

(b) after the temperature of the oil is at about 450 F., blowing the body of oil with steam,

(c) heating said body of oil to a maximum tempera ture of about 580 F. in about 60 minutes time while continuing to blow the oil with steam,

(d) maintaining said conditions of temperature, pressure and steam blowing until an oil viscosity of about 7-10 minutes, Gardner-Holdt, is reached,

(e) lowering the temperature to about 500560 F. and continuing the pressure and steam blowing until a viscosity in the range of from 20 minutes to 75 minutes, Gardner-Holdt, is achieved,

(f) quickly cooling the batch to a temperature below about 475 F., and

(g) dropping the batch into a solvent.

10. A process for making an emulsifiable superbodied alkali refined linseed oil free from gel particles and false body, and having a viscosity of about 50 to 60 minutes, Gardner-Holdt, which comprises the steps of:

(a) charging a body of alkali refined linseed oil to a varnish kettle,

(b) blowing said oil with an inert gas,

(c) applying a vacuum of about 28" of mercury,

(d) heating the oil to about 450 F.,

(e) contacting said hot oil with steam while maintaining the flow of inert gas under vacuum,

(f) heating said oil to a maximum temperature of about 575 F. in about 60 minutes time while contining to blow the oil with steam,

(g) maintaining said conditions of temperature, pressure and steam blowing until an oil viscosity of about one minute Gardner-Holdt is achieved,

(h) adding to said oil at such viscosity from about 0.1 to about 0.5% by weight of the oil of a lead soap, soluble in said oil, said soap being a lead soap of an aliphatic monocarboxylic acid containing from to 22 carbon atoms,

(i) adding to said oil also at said viscosity of about one minute, Gardner-Hol-dt, from about 0.002% to 0.010% of an alkali metal as a soap of an aliphatic carboxylic acid soluble in said oil,

(j) continuing the heating of said oil at a temperature of about 580 F. for a period of time suflicient to give .a viscosity of about 7 to 8 minutes, Gardner- Holdt, while continuing to blow the oil with steam,

(k) dropping the temperature in about 30 minutes from its maximum of about 580 F. to about 550 F. while maintaining the vacuum and steam blowing,

(1) adding to said oil over a period of about 30 minutes at said viscosity of about 8 minutes, Gardner- H-oldt, from about 0.5% to about 1.5% by weight of the oil of a polyhydric alcohol containing from 3 to 10 carbon atoms and at least 3 hydroxyl groups,

(In) continuing heating of said oil at a temperature of about 550 F. at the same pressure while con tinuing to blow the oil with steam for a period of time sufficient to raise the viscosity to about 24 minutes Gardner-Holdt,

(11) allowing the temperature to fade to about 500 F. and holding the conditions of pressure and steam flow until a viscosity of about 50-60 minutes, Gar-dner-Holdt, is obtained,

(0) suddenly cooling the body of oil to about 450 F.

to'arrest further polymerization thereof, and

(p) dropping the bodied oil into a solvent.

11. The product produced by the process of claim 10.

References Cited UNITED STATES PATENTS 496,988 5/1893 Blackeman 260-407 1,745,877 2/ 193 0 Thurman 260-407 2,607,784 8/1952 Arvin 260407 NICHOLAS S. RIZZO, Primary Examiner.

F. A. MIKA, Assistant Examiner. 

1. A PROCESS FOR MAKING A SUPER BODIED UNSATURATED FATTY OIL FREE FROM GEL PARTICLES AND FALSE BODY, AND HAVING A VISCOSITY IN THE RANGE OF FROM 20 MINUTES TO 75 MINUTES, GARDNER-HOLDT, WHICH COMPRISES THE STEPS OF: (A) HEATING A BODY OF SAID OIL UNDER SUBATMOSPHERIC PRESSURE TO THE TEMPERATURE OF INCIPIENT POLYMERIZATION FOR SAID OIL, (B) CONTACTING SAID BODY OF OIL WITH WATER VAPOR AT SAID TEMPERATURE, (C) INCREASING THE TEMPERATURE OF SAID BODY OF OIL TO A MAXIMUM TEMPERATURE NOT IN EXCESS OF ABOUT 615* F. TO INITIATE AND SUSTAIN THERMAL POLYMERIZATION OF THE OIL WHILE CONTINUOUSLY CONTACTING THE BODY OF OIL WITH WATER VAPOR, (D) MAINTAINING THE BODY OF OIL UNDER THERMAL POLYMERIZATION CONDITIONS UNTIL THE VISCOSITY OF THE OIL REACHES A MAXIMUM VISCOSITY IN THE RANGE OF FROM ABOUT 20 MINUTES TO ABOUT 75 MINUTES, GARDNERHOLDT, WHILE CONTINUOUSLY CONTACTING THE BODY OF OIL WITH WATER VAPOR, (E) DISCONTINUING THE CONTACTING OF SAID BODY OF OIL WITH WATER VAPOR, AND (F) CHECKING THE OIL BY RAPIDLY DROPPING THE TEMPERATURE TO BELOW THAT REQUIRED TO SUSTAIN THERMAL POLYMERIZATION. 